Abstract: The internal temperature of an electrochemical device may be probed without a thermocouple, infrared detector, or other auxiliary device to measure temperature. Some methods include exciting an electrochemical device with a driving profile; acquiring voltage and current data from the electrochemical device, in response to the driving profile; calculating an impulse response from the current and voltage data; calculating an impedance spectrum of the electrochemical device from the impulse response; calculating a state-of-charge of the electrochemical device; and then estimating internal temperature of the electrochemical device based on a temperature-impedance-state-of-charge relationship. The electrochemical device may be a battery, fuel cell, electrolytic cell, or capacitor, for example. The procedure is useful for on-line applications which benefit from real-time temperature sensing capabilities during operations. These methods may be readily implemented as part of a device management and safety system.

Abstract: Electrodes comprising an alkali metal, for example, lithium, alloyed with nanostructured materials of formula SizGe(z-1), where 0<z?1; formula SizGe(z-1), where 0<z<1; and/or germanium exhibit a combination of improved capacities, cycle lives, and/or cycling rates compared with similar electrodes made from graphite. These electrodes are useful as anodes for secondary electrochemical cells, for example, batteries and electrochemical supercapacitors.

Abstract: Electrodes comprising an alkali metal, for example, lithium, alloyed with nanostructured materials of formula SizGe(z-1), where 0<z?1; formula SizGe(z-1), where 0<z<1; and/or germanium exhibit a combination of improved capacities, cycle lives, and/or cycling rates compared with similar electrodes made from graphite. These electrodes are useful as anodes for secondary electrochemical cells, for example, batteries and electrochemical supercapacitors.

Abstract: Electrodes comprising lithium alloyed with nanostructured silicon materials exhibit improved capacities, cycle lives, and/or cycling rates compared with similar electrodes made from bulk silicon. The electrodes do not require a conductive diluent such as carbon black. These electrodes are useful as anodes for secondary electrochemical cells, for example, batteries and electrochemical supercapacitors.